Reloading the kernel with kexec before other services start

[Mario Castelán Castro <marioxcc.MT@yandex.com>]

Hello.

I need to reload the same kernel that the machine boots with with kexec, 
in order to specify different kernel parameters. Changing the boot 
loader is unfortunately not an option.

I'm using Debian Wheezy with sysvinit. I can make a script to kexec the 
kernel just once (avoiding loops), but how should I modify/add the init 
scripts so that on boot, this scripts is loaded before the system 
daemons (to prevent corrupting their files when they're ungratuitously 
terminated)?.

Modifying /etc/rc2.d is discouraged as far as I can tell, because the 
scripts there get overwritten by update-rc.d.

Regards and thanks.